China has launched a domestic communications satellite for Pakistan’s SUPARCO (Space and Upper Atmosphere Research Commission) at 16:15UTC on August 11 from the Xi Chang Satellite Launch Center, in Sichuan Province. The launch of Paksat-1R was conducted by the Long March 3B/E (Chang Zheng-3B/E) launch vehicle.
Chinese Launch:
The Paksat-1R satellite is based on the DFH-4 platform, with a launch mass around 5,200 kg. The satellite will be positioned at 38.0 degrees East, replacing the Paksat-1 (23779 1996-006A), which was launched as Palapa-C on January 31, 1996, by an Atlas-IIAS (AC-126) from Cape Canaveral’s LC-36B launch complex.
Paksat-1R was manufactured by the China Great Wall Industry Corporation (CGWIC), after being ordered in October 15th, 2008 – with a contract signed with the China Great Wall Industry Corporation (CGWIC). The PakSat-1R contract was the third communications satellite contract signed by China’s space industry with international customers. It is also China’s first satellite in-orbit delivery contract signed with an Asian customer.
The satellite will support all conventional and modern Fixed Satellite Service (FSS) applications, with a total of up to 30 transponders: 18 in Ku-band and 12 in C-band. To ensure high degree of reliability/availability of the system, two fully redundant Satellite Ground Control Stations (SGCS) were established in Karachi and Lahore, one to act as the Main and the other as Backup respectively.
The DFH-4 (DongFangHong-4) platform is a large telecommunications satellite platform – a new generation of hardware based on high output power and communication capacity, ranking alongside international advanced satellite platforms.
The applications for the DFH-4 platform aren’t limited to high capacity broadcast communication satellites and can be used to tracking and data relay satellites, regional mobile communication satellites, etc.
The platform comprises propulsion module, service module and solar array. It has a payload capacity of 588 kg and an output power of 10.5 kW by the end of its lifetime. Its design lifetime is 15 years and its reliability by the end of its lifetime is more than 0.78.
Based on versatility, inheritance, expandability and promptness principles and mature technology, the platform will meet the needs of international and domestic large communication satellite markets.
The satellite is equipped with three receiver antennas and two transmission antennas. It can support the transmission of 150-200 TV programs simultaneously to ground users using a 0.45m antenna device.
The DFH-4 satellite also features strong capabilities against hostile interference and jamming. The satellite’s power supply includes two 6m solar panels. The dimensions of the DFH-4 bus are 2.360 m x 2.100 m x 3.600 m.
Developed in the basis of the CZ-3A Chang Zheng-3A, the CZ-3B Chang Zheng-3B is the most powerful launch vehicle on the Chinese space launch fleet.
The CZ-3B features enlarged launch propellant tanks, better computer systems, a larger 4.2 meter diameter payload fairing and the addition of four strap-on boosters in the core stage which provide additional help in the first phase of the launch.
The rocket is capable of launching a 11.200 kg satellite to a low Earth orbit or a 5,100 kg cargo to a geosynchronous transfer orbit. The rocket has a total length of 54.84 meters and a core diameter of 3.35 meters.
After its first failed launch of the February 14, 1996 but ended in failure in what is now known has the “St. Valentine’s Day Massacre”, all the launches of the CZ-3B were successful, except the launch of Palapa-D on August 31st, 2009.
During that failure, the third stage failed to restart for the second burn and the satellite was left on a lower than planned orbit. Later, the apogee motor of the satellite was used for a maneuver to put the satellite on the geostationary orbit.
In recent years, the CZ-3B/E (Enhanced Version) launch vehicle was developed on the basis of CZ-3B, increasing the GTO capacity up to 5.500kg. The CZ-3B/E has nearly the same configurations with CZ-3B except its enlarged core stage and boosters. On May 14, 2007, the first flight of CZ-3B/E was performed successfully, accurately sending the NigcomSat-1 into pre-determined orbit.
With the GTO launch capability of 5.500kg, CZ-3B/E is dedicated for launching heavy GEO communications satellite.
This was the 144th successful Chinese orbital launch, the 142nd launch of a Chang Zheng launch vehicle, the sixth launch from Xi Chang in 2011, and the seventh orbital launch for China in 2011.
The Xi Chang Satellite Launch Centre is situated in the Sichuan Province, south-western China and is the country’s launch site for geosynchronous orbital launches.
Equipped with two launch pads (LC2 and LC3), the centre has a dedicated railway and highway lead directly to the launch site. The Command and Control Centre is located seven kilometres south-west of the launch pad, providing flight and safety control during launch rehearsal and launch.
Other facilities on the Xi Chang Satellite Launch Centre are the Launch Control Centre, propellant fuelling systems, communications systems for launch command, telephone and data communications for users, and support equipment for meteorological monitoring and forecasting.
The first launch from Xi Chang took place at 12:25UTC on January 29, 1984, when the CZ-3 Chang Zheng-3 (CZ3-1) was launched the Shiyan Weixing (14670 1984-008A) communications satellite into orbit.
August schedule:
Rumors have surfaced relating to launch of TG-1 TianGong-1, noting it may take place at the end of August.
After passing its production certification, Tiangong 1 arrived at the launch site via railway on June 29 to undergo its final testing. The CZ-2F Chang Zheng-2F launch vehicle was delivered on Jiuquan Satellite Launch Center on the morning of July 23.
At the end of the month, China plans to launch the first HY-2 Hai Yang-2 oceanographic satellite from the Taiyuan Satellite Launch Center. Rumours also point for a possible launch of the SJ-11 ShiJian 11-04 satellite from Jiuquan.
Finally, the launch of the Shiyan Weixing-4 and Chuang Xin-3 pair from the Jiuquan has been delayed to September.
(Images: Chinanews.com)